Rob
Forum Moderator

We've modelled enough things over the years to be fairly confident that just about anything can be modelled, although whether that's a good idea is something we're less confident of. I'm the one who spent 3-4 weeks building a lung mesh off an MRI because it seemed like a good idea at the time..... Turns out it was a good idea, and the technology means it'll take a lot less time now. 

Soil is complicated, and resistance coefficients will depend on what sort of soil you have. The Ergun Equation approach might be a good starting point. Otherwise, you're going to need a friendly geologist with a lab.